The invention relates to a door coupling according to the preamble of claim 1 for a door of a motor vehicle, in which the door can be displaced with respect to a door pillar in a transverse movement combined with a pivoting movement by means of a four-joint mechanism, the four-joint mechanism having a supporting arm connected in an articulated manner to the door and in an articulated manner to the door pillar and a control rod connected in an articulated manner to the door and in an articulated manner to the door pillar, the supporting arm being fastened in an articulated manner with regard to the door and pillar at in each case two gudgeons assigned to the end regions of the supporting arm.
U.S. Pat. No. 3,275,370 describes a door which is coupled to a motor vehicle via a four-joint mechanism and in which a plate-like supporting arm is designed in the form of a rectangle arranged rearward and having four gudgeons which are arranged in the region of the corners, which define an axis inclined with respect to the vertical on each side of the supporting arm, while a control rod in the frontal region of the door controls the displacement movement of the door. In the case of the known mechanism, the hinge leaves which, together with said gudgeons, define the other part of the joints are fastened to the door assembly parts, the door and door pillar, without any possibility of fine adjustment in order to correct installation and manufacturing tolerances.
U.S. Pat. No. 3,095,600 describes a door which is coupled to a motor vehicle via a four-joint mechanism and in which an upper and a lower supporting arm having respectively laterally offset joints, and a control rod are provided, in order to arrange the door in a pivotable manner on the vehicle. In the case of imprecise fastening, this type of coupling causes at least a stiff type of coupling. All possible freedoms in the fastening of the door are required for the coupling functioning to some extent, so that asymmetrical arrangements, occurring on account of dimensional, manufacturing and installation tolerances, of the door in the corresponding opening of the vehicle body cannot be corrected.
EP-A-0 569 403 describes a door which is coupled to a motor vehicle via a four-joint mechanism and in which the four-joint mechanism is formed in a four-joint hinge whose hinge brackets on the door and on the pillar each have a coupling to a joint of a supporting arm and a joint of a control rod, the supporting arm furthermore having joints which are defined by individual hinges in alignment with the supporting-arm joints which are provided on the hinge brackets. The supporting arm is circumscribed within its gudgeons by a rectangle. In order for the door to be adjustable, the control rod is divided into two halves which can be mutually fixed by screw bolts interacting via holes, as a result of which, for example, the rearward joint of the supporting arm adopts a different position relative to the frontal joint of the control rod, and thus has the theoretical possibility of changing the position of the door in the vehicle body about the vertical, in which case there are only two alternatives here. However, asymmetrical arrangements, occurring on account of dimensional, manufacturing and installation tolerances, of the door in the opening of the vehicle body cannot be corrected sufficiently precisely.
U.S. Pat. No. 4,665,586 describes a door which is coupled to a motor vehicle via a four-joint mechanism, in which an upper and a lower four-joint mechanism are each formed from a control rod and from a common, plate-like supporting arm, there being no possibility at all of correcting the orientation of the door in the vehicle body.
During installation of a motor vehicle door, the door has to be adjusted in its position with respect to the vehicle body in the x-, y- and z-direction. In this case, the x-direction stands for the direction of travel, y for the horizontal direction transversely with respect to x, and z for the vertical direction transversely with respect to x. In the case of a pivot-out door hinge, during the adjustment of the door with respect to the vehicle body a defined setting of the supporting arm of the hinge on the interior door molding also has to take place, so that the part of the interior door molding which is fitted on the supporting arm can be fixed in place in a positionally correct manner with respect to the dashboard etc. This adjustment requirement greatly reduces the adjustment options in the mounting of the door carcass onto the hinge. In the case of single-hinged pivot hinges, the adjustment in order to compensate for an angular offset between the screw-down surfaces on the door and on the door pillar can take place by determining the y- and z-coordinates. In the case of the pivot-out door hinge, this adjustment option is used up by the necessity of adjusting the supporting arm with respect to the interior door molding. Therefore, in the case of a pivot-out door hinge, an adjustment by rotating about the x-axis is additionally required. Moreover, for tolerance reasons, when installing the door it may be necessary, in the case of a multi-joint door hinge, to compensate for an angular offset between the screw down surfaces of the hinge and door panel in order to fix the positioned door onto the hinge. Such compensation can only be corrected by twisting the hinge leaf. This adjustment can take place only by changing the distance between the coupling axes of the control rod on the door and door pillar. The known solutions for changing the length of the control rod are very complicated both to produce and to install.
It is the object of the invention to provide a door coupling that enables the door position in the vehicle body to be influenced in a simple and effective manner. The door can be displaced with respect to a door pillar in a transverse movement combined with a pivoting movement by means of a four-joint mechanism, the four-joint mechanism having a supporting arm connected in an articulated manner to the door and in an articulated manner to the door pillar and a control rod connected in an articulated manner to the door and in an articulated manner to the door pillar, the supporting arm being fastened in an articulated manner with regard to the door and pillar at in each case two gudgeons assigned to the end regions of the supporting arm.
This object is achieved for the door coupling in that the supporting arm has a base supporting arm and at least one supporting arm part that can be detached from said base supporting arm and comprises the two gudgeons provided at one end of the supporting arm, and means for the mutual fastening of the base supporting arm and supporting arm part, and in that an axis passing through the tangent plane of the base supporting arm and supporting arm part allows adjustment of the supporting arm part with respect to the base supporting arm by mutual twisting around a pivot axis which is perpendicular with respect to the tangent plane.
The door coupling according to the invention has a supporting arm which can be divided into a base supporting arm and at least one supporting arm part which can be detached from said base supporting arm and comprises the two gudgeons provided on one side of the supporting arm, the base supporting arm and supporting arm part expediently having flat sides which face each other and define a tangent plane which guides at the same time to a pivoting movement of the supporting arm part relative to the base supporting arm in the manner of a stop. The base supporting arm and supporting arm part are mutually clamped together by means for the mutual fastening, preferably screws or the like, these means being of releasable design in order to permit mutual twisting of the supporting arm part and base supporting arm around a pivot axis which is perpendicular with respect to the tangent plane. The pivot axis is defined by an axis passing through the base supporting arm and supporting arm part, said axis possibly not having the same orientation as the pivot axis, in which case the pivot axis is defined perpendicularly with respect to the tangent surfaces by the location at which the axis passes through. It is therefore possible, for example, to provide just one pin protruding out of one of the tangent surfaces in order to define the pivot axis, while the fastening at other points is provided by means of a screw connection or the like.
One particular advantage of the door coupling according to the invention is that the pivoting of the supporting arm part and base supporting arm relative to each other about relatively small angles enables the position of the door in a recess, formed for this purpose, in the vehicle body to be corrected essentially around the x-axis, which corresponds to the direction of travel in the case of motor vehicles. This enables manufacturing and installation tolerances in the fitting of the door, which tolerances lead to a visually unattractive asymmetry or tilting relative to the vehicle body, to be corrected in a particularly simple and efficient manner, a correction, particularly in the case of a four-joint mechanism which defines the pivoting-out movement of the door, at the stop points of the hinge parts on the door or door pillar being made more difficult by the fact that the determination of the position relative to the interior door molding uses up the known paths of adjustment.
In contrast, the door coupling according to the invention enables readjustment of a door which has already been fastened, in that screws are provided, preferably on the rearward supporting arm part, said screws enabling the supporting arm part to be detached and enabled around the pivot axis in order to correct the position of the door around an axis essentially parallel to the horizontal.
The tangent plane of the base supporting arm and supporting arm part is expediently not only passed through by a central or eccentric screw for defining the pivot axis, but furthermore also by further fixing and/or guide elements which are displaced on a circular path around the pivot axis in a radius corresponding to this distance from the pivot axis. For this purpose, the fixing and/or guide element, which is preferably designed as a screw, is screwed into one of the two partsxe2x80x94the base supporting arm and supporting arm part, while a slot, which also has a little vertical play, is provided in the other of the two parts in order to enable the screw shank to undergo, within the slot, a displacement corresponding to a short circular segment. As an alternative to a slot having vertical play, it is also possible to shape the slot to correspond to the circular segment and to reduce the play radially corresponding to the circular segment. This last variant has the advantage that the base supporting arm is effectively prevented from dropping during the pivoting on account of the vertical play of the supporting arm part.
The tangent plane is to be understood as being a plane in the widest sense, i.e. it is not required for the tangent plane to spatially coincide with a surface. Rather, it is possible for the tangent plane to comprise a plurality of sections, for example a displacement section which is laterally offset with respect to that section at which the means for fastening the base supporting arm and supporting arm part pass through the tangent plane. The tangent plane could therefore, for example, have a dome shape which, in the case of a symmetrical design, would readily permit the pivoting movement, for example. Furthermore, the tangent plane could be formed from axially offset circular sections which would likewise permit pivoting.
In the case of the arrangement according to the invention as a four-joint mechanism, the supporting arm serves essentially to transmit the load from, in particular, large and therefore heavy doors onto the motor vehicle and, in particular, onto its door pillar which is arranged in the region of the A-post. For this purpose, the supporting arm is formed in the manner of a plate body in whose four corner regions the gudgeons for the coupling to the door and to the pillar are formed. The supporting arm part is expediently fastened detachably on that side of the base supporting arm which faces the door, since it is particularly readily accessible there for adjusting the orientation with respect to the base supporting arm. However, it is also possible, as an alternative thereto or in addition thereto, to provide a supporting arm part on the frontal side of the supporting arm, which side is coupled to the door pillar, as a result of which, in a manner which is similar and scarcely changed in outcome, the orientation of the door in the recess left free in the vehicle body can be influenced by rotation around the x-axis. However, it will, as a rule, be sufficient to provide just a two-part design of the supporting arm.
It should be noted that the supporting arm part, the two supporting-arm gudgeons being formed integrally on it, connects in respect of their alignment and spacing the two gudgeons in the manner of a strip and thus provides the supporting arm part to form an integral part to become a mass-produced product which can therefore be positioned without any outlay on adjustment, with the result that even by means of a four-joint mechanism the door coupling according to the invention obtains an adjustability (which is otherwise not present) of the position of the door around the x-axis.
A significant advantage of the two- or multi-part design of the supporting arm also resides in the more economical possibility of producing the base supporting arm from an extruded profile, in which the region between the gudgeon portion bearing the gudgeons is produced as an independent supporting arm part and is not obtained as a costly waste of material. In addition, the base supporting arm can be produced cost effectively by extrusion, as a result of which the mechanical further processing in order to expose the gudgeon portion is additionally dispensed with.
According to a particularly preferred development of the invention, the control rod is of single-piece design and with regard to the door or pillar is coupled to a bearing plate to which a corresponding gudgeon of the supporting arm, preferably the lower gudgeon, is also coupled, where the end remote from the abovementioned side of the control rod is coupled to a hinge part which can be fastened in a manner enabling it to be displaced jointly with and in the direction of the control rod relative to a corresponding hinge part assigned to gudgeon of the supporting arm. The hinge part of the supporting arm and the hinge part of the control rod can be fastened to a door assembly part, door or door pillar, using the same screws, and this connection is hence at the same time a connection of the two door hinges, as a result of which the four-joint mechanism is defined in the four-joint hinge defined by this means. It is alternatively possible, with the same outcome, to fasten the hinge part of the control rod to the hinge part of the supporting arm and to fasten one of the two hinge parts to the door assembly part, door or door pillar, since by fastening the two hinge parts to each other the joint axes of the control rod and supporting arm are defined relative to each other, so that a defined four-joint hinge is formed by this means.
A particular feature of this design is that the two hinge parts can not only be connected together, but, moreover, the connection can also be displaced in the direction of the control rod, which has the consequence that the relative position of the two joint axes with respect to each other can be changed, a change in the distance between the two joint axes in the closed position of the door having the consequence of enabling said door to pivot around an axis running essentially vertically.
By providing the possibility of mutual displacement, which expediently is to take place in an infinitely variable manner, a particularly precise and sensitive correction of an offset of the motor vehicle door in the corresponding recess of the vehicle body is possible, in which case, as a function of the increase or reduction in the distance between the two joint axes, the vehicle door is pivoted around an essentially vertical axis in the direction of its rearward edge or the direction of its front edge, if it is presumed that the control rod is engaging further forward than the supporting arm.
The relative displacement of the two hinge parts can take place in a particularly simple and expedient manner by a slot running essentially in the direction of the x-axis (with the door closed) being formed in at least one of the two hinge parts, a customary screw/nut combination being passed through said slot and, when the desired position is reached, being tightened in order to finally fix the two door hinges in place. There is virtually self-centering when the door is fitted.
According to an alternative embodiment, it is possible to ensure the alignment of the vehicle door, in particular the rotation about the vertical, by the fact that the supporting arm and control rod are coupled with regard to the door and/or pillar to hinge parts which are not connected to each other and can be fastened to the corresponding door assembly part, as a result of which the adjustability is provided in a manner known per se by slots, for example in the region of the supporting arm part or hinge part, with acceptance of an increased outlay on installation.
According to a variant to be formed in a simple manner, the four-joint mechanism, which is designed as a four-joint hinge, can also be coupled to a rigid bearing plate as a four-joint hinge if the control rod is then divided and the two parts of the control rod, relative to each other, lead to a lengthening or shortening of the control rod, with the same outcome of precision adjustment as is achieved by pivoting around a vertical axis. The lengthening can be obtained, for example, by spindle-nut systems or by mutual latching positions of the divided control rod.
Further advantages and features of the invention emerge from the dependent claims and from the following description.